ORIGINAL: mscic-RCU
I fly mine a Webra .61 ringed 11X7 prop. Seems to be a real good match.
What muffler are you using on your Webra .61 I just put one on my Bobcat and took off the 55AX I had on it. I mounted a Tower 75 muffler to the Webra hoping to get decent performance on FIA fuel.
Dauntae